/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package com.ht.safe.security;

import com.ht.scada.security.entity.User;
import com.ht.scada.security.entity.UserRole;
import com.ht.scada.security.service.UserService;
import org.apache.shiro.authc.*;
import org.apache.shiro.authc.credential.HashedCredentialsMatcher;
import org.apache.shiro.authz.AuthorizationInfo;
import org.apache.shiro.authz.SimpleAuthorizationInfo;
import org.apache.shiro.crypto.hash.Sha256Hash;
import org.apache.shiro.realm.AuthorizingRealm;
import org.apache.shiro.subject.PrincipalCollection;
import org.springframework.beans.factory.annotation.Autowired;

import java.io.Serializable;
import java.util.Objects;

public class ShiroDbRealm extends AuthorizingRealm {

    public static final int HASH_INTERATIONS = 1024;
    protected UserService userService;

    public ShiroDbRealm() {
        setName("SampleRealm"); // This name must match the name in the User
        // class's getPrincipals() method
        //设定Password校验的Hash算法与迭代次数.
        setCredentialsMatcher(new HashedCredentialsMatcher(Sha256Hash.ALGORITHM_NAME));
//		HashedCredentialsMatcher matcher = new HashedCredentialsMatcher(Sha1Hash.ALGORITHM_NAME);
//		matcher.setHashIterations(ShiroDbRealm.HASH_INTERATIONS);
//		setCredentialsMatcher(matcher);
    }

    @Autowired
    public void setUserService(UserService userService) {
        this.userService = userService;
    }

    /**
     * 认证回调函数,登录时调用.
     */
    @Override
    protected AuthenticationInfo doGetAuthenticationInfo(
            AuthenticationToken authcToken) throws AuthenticationException {
        UsernamePasswordToken token = (UsernamePasswordToken) authcToken;
        User user = userService.getUserByUsername(token.getUsername());
        if (user != null) {
            return new SimpleAuthenticationInfo(new ShiroUser(user.getId(),
                    user.getUsername(), user.getName()), user.getPassword(),
                    getName());
        } else {
            return null;
        }
    }

    /**
     * 授权查询回调函数, 进行鉴权但缓存中无用户的授权信息时调用.
     */
    @Override
    protected AuthorizationInfo doGetAuthorizationInfo(
            PrincipalCollection principals) {
        ShiroUser shiroUser = (ShiroUser) principals.getPrimaryPrincipal();
        User user = userService.getUserByUsername(shiroUser.userame);
        if (user != null) {
            SimpleAuthorizationInfo info = new SimpleAuthorizationInfo();
            UserRole role = user.getUserRole();
            info.addRole(role.getName());
            info.addStringPermissions(role.getPermissions());
            return info;
        } else {
            return null;
        }
    }

    /**
     * 自定义Authentication对象，使得Subject除了携带用户的登录名外还可以携带更多信息.
     */
    public static class ShiroUser implements Serializable {

        private static final long serialVersionUID = -1373760761780840081L;
        public Integer id;
        public String userame;
        public String name;

        public ShiroUser(Integer id, String username, String name) {
            this.id = id;
            this.userame = username;
            this.name = name;
        }

        public String getName() {
            return name;
        }

        /**
         * 本函数输出将作为默认的<shiro:principal/>输出.
         */
        @Override
        public String toString() {
            return userame;
        }

        /**
         * 重载hashCode,只计算loginName;
         */
        @Override
        public int hashCode() {
            return Objects.hashCode(userame);
        }

        /**
         * 重载equals,只计算loginName;
         */
        @Override
        public boolean equals(Object obj) {
            if (this == obj) {
                return true;
            }
            if (obj == null) {
                return false;
            }
            if (getClass() != obj.getClass()) {
                return false;
            }
            ShiroUser other = (ShiroUser) obj;
            if (userame == null) {
                if (other.userame != null) {
                    return false;
                }
            } else if (!userame.equals(other.userame)) {
                return false;
            }
            return true;
        }
    }
}
